Described herein is a concentrated, low viscosity hair care composition that is stable and can also be delivered to the hair in various forms including a foamed form. Delivery of cleansing composition in the form of foam is desirable to the consumer. The low density of the foam necessitates a high surfactant composition in order for the consumer to receive the appropriate level of cleansing in a realistic product volume in one dose. However, typically, high surfactant liquid cleansing composition exhibit high viscosity, which makes it difficult to deliver via a pump foam dispenser, a squeeze foam dispenser or an aerosol foam dispenser. Therefore, delivery as a foam is facilitated by low viscosity compositions that contain a high concentration of cleansing surfactants.
Mechanical or pump foams for the personal cleansing category represent an attractive form to the consumers. A hair care product delivered via foam is readily spread on hair and enables hair cleansing without leaving significant residue on hair because the structuring effect of foam enables the use of compositions without polymeric or waxy structurants. Because of the low density of the foam, high concentration of surfactant is required to deliver sufficient amount of detersive surfactant for each use. However, high surfactant liquid cleansing compositions often exhibit high viscosity, which makes it difficult to deliver with a typical pump foam dispenser. High surfactant liquid cleansing compositions can become unstable and phase separate. Based on the foregoing, there is a need for a low viscosity, stable, concentrated liquid cleansing composition for delivery as foam. In addition, the combination of clear product in a clear container is visually appealing. Thus, there is a need for developing transparent or translucent compositions. High content surfactant compositions may be prepared by using surfactants that have tails with short alkyl chains (10 to 11 carbon atoms). This approach can result in a less mild composition. Thus, there is a need to prepare mild surfactant compositions having low content of surfactants with a tail having an alkyl chain with 10 or 11 (or lower) carbon atoms.
It has been surprisingly found that clear, stable, low viscosity compositions having high surfactant content can be prepared by using linear sulfates (with alkyl tail of 12 carbon atoms or above) and branched sulfates (with alkyl tail of 12 carbon atoms or above), a water-miscible solvent such as dipropylene glycol or glycerin. Suitable compositions have a ratio of (Linear anionic surfactant/Branched anionic surfactant)/Miscible solvent lower than about 0.2 and a ratio of (Branched anionic surfactant/Miscible solvent) lower than about 5.